The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingConnecting a bluetooth®
device
Up to 5 bluetooth® devices (phones (hfp) and audio players
(avp)) can be registered.
If more than 1 bluetooth® device has been registered, select
which device to connect to.
Press the “setup” button.
Select “bluetooth*”.
*: Bluetooth is a registered trademark of bluetooth sig ...
Spiral cable
Components
Removal
Caution:
Be sure to read the precautionary notices concerning the
srs airbag system before servicing it (see page rs-1).
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery ...
Components
...